So, we can play and create our own language, or just keep using Perl5 on it.

I think that it's even better than that. You should be able to write your code in multiple languages that integrate together completely since they're running on the same VM. I worked in an environment that allowed this earlier in my career (more info here) and it's really nice.

The bigger problem will be to rewrite the Perl modules at CPAN, specially modules with XS.

An evil solution to this occurred to be last night. Keep Perl5 around, create a Perl5 server, and use RPC/IPC from Perl6 to run the XS code that you need.

Now, if only there was a language that allowed you to hack stuff like that together really quickly :-)